Automatic feed head



Feb. 6, 1940. c. E. BRODERS AUTOMATIC FEED HEAD 0r igi nal F iled May 5, 1933 INVENTO'R (712422 fifm-fs MW in ATTORNEY breakage of the tool results. I Devices heretofore proposed. iflwWhlChiWDil'iIq ugal force is utilized tomove a rotating tool have i been adaptations. of the conventional .bali'and lever type of mechanism commonly employed as I Reiuued Feb. 6, 1940 li a"). c 1

[.nurotmhc FEED amp .g{clauseKareem/Deficit. Mica, assigno r', liyf f s ,mesne assignment Victor Gauvreau, De

' ,foriginal.No illdilili;dated September a, 19st,

. Seriai. 869,226, May 3, 1933. .Application forreissue May 11, 1938, Serial No. 208,372 7 My. inventionrelates a feed and -more particularly, to a centrifugally operated feedhead adaptedfor.useinconnection withcutting, mill-{ ing, reaming, or, drilling, operations inwhich the particular tool tobe employed is rotating while advancing ;toward the object to I be -;worked .upon..

As a further feature jof my invention the tooluis, returned automatically; to its initial. position after 7 I a head.

being move ea edete in min Prior, to. my invention automatic feed heads havebeen proposedin which fluid pressuresor mechanically operated cams and levers have been utilized to cause a movementof a toolrtow ard the object to be worked upon. In-order-to-use such devices as a part of an automatic machine',, it is necessary to provide means for operating the feed head'in additionto power meansiondrivingthe tool..-; This requirment adds greatly the ex,- pense of,v such machines and greatlyrlessensthe utility, of such devices; in automaticgmachine work.

Mechanically. operated feed heads heretofore known have been unsatisfactory alSOxd'ilEtUBX- cessive breakage of tools whenencountering a hard spot" in the work. The increased resist pressures that ance to the tool builds up such governors in various types ofmachinesni'have' type is known to lose its efliciency the further the rotation throws the weighted ballsfi As the balls v move to the positions farthestremovedfrom their positions of rest, the effective lengthsoi' the-con nected levers are shortened and con'seque'ntlythe :P 'H B Y P 8. 1. l0 designa e a convenpressures exerted on the tool are diminished. In

contrast to this effect, a device embodying my inres; I p l mover, inasmuch'as my invention is adapted for ventionshows an approximately constant sure exerted on the tool at all times.

It is, therefore, an object of my present in-" vention to provide an automatic feed head in which centrifugal force is used to advance a tool, ne

the forces utilized being built up by the means'utilized for operation of the tool.

to a predetermined point. i

It is a further object of my present invention to. provide an automatic feed head in forces exerted by the feed head may be definitely controlled and variedto meet the requirement of different types of materials and different operations 'to be performed thereon.

It is a further object of mypresent invention to provide an automatic feed head in which predetermined and approximately constant pressures are exerted on the toolactuated by the feed It is a further object of my present invention ,to provide an automatic feed, head which is of such a design and constructlonas to be inexpensive to manufacture, positivein operation, and adapted for convenient utilization in all types of :automatic machines in which it is desired to ad- 7 vance a rotating tool to a predetermined point, and then automatically return the tool to its initial position. a

--These and various other. objects, features of arrangement, construction and operation, are

plainly shown and described and will be best understood by reference to theaccompanying drawing, in which:

Fig.1 is a longitudinal, sectional view of a feed head embodying my invention, mounted on the shaft of an electric motor partially shown in side elevation;

Fig. 2 is a fragmentary section ot a feed head Qembodying my invention, showing the positions of the respective parts after movement of the tool a predetermined distance; r

Fig. 3 is a sectional view taken on the line II of Fig.1;

Fig. 4. is a sectional view taken on the line 4-4 Similar reference numerals refer to similar .parts throughout the several views.

Referring more in detail to the drawing, and

tionaltype of electric motor having a rotating shaft II and is here utilized only as a symbol of p ferred means.

In thepresent embodiment of my invention a housing ills provided, one end of which abuts upon and is supported by the casing of the motor .10, and the'opposite end of which is provided ;wm a,bushlng i l through which extends an ad- Justable latch release sleeve M, which is secured in any'desired position by a lock nut l5.

Tool holdingfmeans: ID of any desired type are secured'to adriven' plunger I], which extends gthroughthe drive sleeve II on which the adjustis tends inside the main spring 22. A latch spring able latch release sleeve it isscrew-threaded. Thedrivesleeve liisiockedontheshaftll for rotation therewith by a key II or other suitable means. Securedtothedrivesleeve l8 isafixed member 2|. which abuts on a shoulder 2l provided in the drive sleeve ii. A push member 22 is mounted on the drive sleeve II at a distance from the fixed member and is so mounted as to be free for reciprocal longitudinal movement relative to the drive sleeve l8.

A main spring 22 abuts at one end against th push member 22' and at the other end abuts against a. spring stop washer 24. A plurality of plunger latch members 28 are pivotally mounted on the end of the push member 22 which ex- 28 extends around the plurality of latch members 2! and yieldingly holds said latch members in the position shown in Fig, 1. A plunger pin 21 is secured to the driven plunger ll at a suitable point to be contacted by said plurality of latch members 25. The plunger pin 21 is locked in position in the driven plunger member l1 by a. plunger screw 28. A plunger spring 2| abuts at one end against the head of the plunger screw 28 and at the other end against a shoulder ll formed inside the drive'sleeve II, and acts to return the driven plunger l1 after completion of its forward movement; v i

Movement of the-driven member 22 and its attached parts to cause a movement out of the casing l2 of the driven plunger I1 is accomplished by a plurality of separate actuating weights 3|. which occupy the space between the fixed member 2II and the driven member 22. The said actuating weights II are mounted concentrically about the drive sleevel8, and when the drive sleeve II is not rotated occupy the position shown in Fig. l lying closely adjacent to the outer sur-' /face of the drive sleeve It.

The actuating weights 3| are each formed with beveled cam faces 22, which lie adjacent to cam surfaces provided on the fixed member 2l'and the actuating member 22. Rotation of the drive sleeve ll builds up. centrifugal forces within the weights ll and causes the weights 3| to move outwardly from said drive sleeve It. In order to insure positive direction in the outward travel and subsequent return of the weights II, a weight spacing and guiding member 23 is provided. The weight spacing and guiding member 23 is mounted on the drive sleeve II and is preferably splined thereon to insure positive rotation therewith I occupy the position shown in Fig.1. to referringtothisrelationofthepartslshall hereafter use the term "parts at rest.

When the parts are at rest the actuating weights II occupy a position concentric with .and closely adjacent to the drive sleeve ll. spring 28 exerts an approximately constant pressure on the push member 22. which pressure in turn is exerted on the actuating weights 3| and yieldingly maintains the said weights in this p sition. While the parts are at rest the driven plunger I1 is maintained within the drive sleeve II and the drivepin 21 is contacted by the latch members 2|. Upon rotation of the shaft II the weights 8i begin to move outwardly from'the drive sleeve ll until they occupy the position sbownin Pig. 2. As the shaft is rotated, the

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drive sleeve ll and the driven plunger 11 are also rotated and the tool held in the tool holding means ll is caused to rotate. At the same time the fixed member 20 and the push member 22 both are rotated at the same speed as the driven 2| and 22 is such that thedistance which separates the members is less at their outer circumferences than at their points of attachment to the drive sleeve ll. Thus, as the weights 3i move outwardly pressures are exerted on the members 20 and 22, tending to cause relative longitudinal movement of the member 22. The member 20 is fixed to the sleeve l8 and abuts on the shoulder 2i, so that it cannot move in a 1ongitudinal direction. The longitudinal movement of the member 22 compresses the spring 2| and this takes place as soon as sufficient forces are built up in the weights II to overcome theforces present in the spring 23 and the inertia forces in the plunger l1 and its related parts.

As the member 22 moves longitudinally, the latches 2i exert a pushing action on the plunger pin 21, which in turn pushes the plunger 11 causing it to move longitudinally relative to the sleeve ID. This movement compresses the spring 29 and is continued until the plunger i1 has moved a predetermined distance, which is reguplunger I1.

Further rotation of the shaft l I after the parts occupy the position shown in Fig. 2 continues the rotation of the drive sleeve l8 and forces the latches 25 forwardly to a point of contact with the end of the latch release sleeve II. This opens theiatche's 25 against the pressure of the spring 28 and releases the plunger pin 21. Upon release of the plunger pin 21, the spring 29 is freed from compression and returns to its initial position. carrying with it the driven shaft l1 and its related parts. This return of the driven shaft l1 by the action of the spring 29 is independent of the return of the other parts of the assembly and permits'a rapid withdrawal of the tool from the work while the tool is rotating under power. The point of release of the pin 21 may be varied by adjustment of the latch release sleeve I4, and so it is possible to control positively and automatically the point at which forward movement of the tool shall cease. The return of the tool is practically instantaneous and may be accomplished without requiring a stopping of the shaft II or the driven sleeve i8.

After the driven plunger i1 is returned to its initial position, rotation of the shaft II and the driven sleeve I! may be slowed down or stopped. As soon as the speed of rotation is lessened the forces in the weights ll are lessened and the spring 22 is permitted to give up. its compression and return to its initial position.

The forces in the spring 23 are exerted on the member 22 and bring about its return to its Illthe same position after operation as they did The weights II are guided by the spacing and guiding member 31 and so return to occupy P ior to operation" of the The rea caused to snapin'to place in with the plunger pin 21.

, While the preferred method of operation of a device embodying my invention requires a stopping of the shaft II and the driven sleeve I8 to permit the return or the parts to their normal positions, it is possible, to so relate the disposed relative to the drive sleeve I8 andare so placed as to give a balanced rotation of the- I have found that by using six weights of this type it is possible to dispose them on opsleeve I8.

posite sides of the sleeve I8 and to use them in multiples of two, three, or four 'aswell'as the complete number of weights in order to secure different pressures on the tooL, This arrangement will permit four possible variations in pressures on the tool and will be found to be suflicient in the majority of operations in which such a device is used. -If more variation isrdesired, the number of weights may be increased and the selective removal of such weights will give the v desired variations in pressures exerted on the tool.

Each weight is spaced and guided by the member 33, which as shown in Fig. 3 is provided with a plurality of U-shaped grooves 34 corresponding in number to the number of weights 3| to be used in the device. Each weight 3| is formed with a central portion 35, which fits in one of said U-shaped grooves 34 for sliding movement relative thereto. Removal of any of therweights from the assembly is accomplished by the removal of the casing I2 and movement of they member 22 by compression of the spring 23. The desired weight or weights may then be slid from the member 33 from opposite sides of the drive sleeve I8, the remaining weights being maintained in their respective positions after release of the spring 23 and the return of the member 22 to its initial position by the member 33.

It will be observed that if resistance to movement of the tool is encountered the eflect of that resistance is to lessen the speed of the tool without building up any added pressures on the tool.

Thus a feed head embodying my invention eliminates much of the excessivetool breakage caused by feeding devices in which the pressureon the tool is increased as the resistance to the tool increases.

It will be found that if the feed head is constructed as shown in the drawing, the force caused by the centrifugal action of the weights 3i urging the cup 22 forward, will increase a certain fixed amount for each unit of linear distance that the drill is moved and that the force of the spring 23 opposing such movement increases at substantially the same rate, so that the initial difference between these forces remains substantially constant during the operation. The force exerted on the tool is only the difference between these forces, and thus there is a substantiaiiy constant feeding pressure on the tool during the entire feeding operation.

1 claim as new desire "to "Secure,

Patent 0f the'fUnited States 15:. 7

WhiIe -"I have illus'trated a preferred embodifm'ent or my inve'ntion; many: modifications may "be maderwithout departing from :the' spirit or the invention, and l -do -"not wmh to "be" limited to the precise details -01 constructions swims; but" de- 7 "sire 'to avall myselhofiall changes-within the scope of: the appended-claims? I I Having thus 'described my invention, what I by Letters 1. A feed head for feeding a rotating-tool to a work piece at apredetermined. substantially tween saidv members and movable outwardly thereof .upon rotation of said shaft to effect sliding' movement of said push rmember on said sleeve, a tool'holder carried by said sleeve and slidable longitudinally thereof, :a ;relei.tsablev connection between said push member and said tool holder and comprisingpivoted dogs carried on said push member and contacting with said tool holder to projectsaid tool holder from the body upon the'rotation of said shaftand sliding movement of said push member, a stop-operable to release said dogs upon a predetermined amount of projection of said tool holderiromsaid body, and a spring for retracting saidtool-holder after release of the connectionwith said push member.

2. A feed head comprising a sleeve fixed to a rotating shaft, a fixed memberand a push memher mounted on said sleeve, a plurality of centrifugally actuated weights disposed between said members concentrically of said sleeve and movable outwardly thereof and relative to said members upon rotation of the sleeve'thereby to move said push member axially thereof, a tool holding member carried by said sleeve and slidable relative thereto, means carried by said push member and engaging said tool holder for projecting said tool holder outwardly from said sleeve, a member for releasing the connection between said push member and said tool holder after projection of said tool holder to a predetermined point, and a spring for thereafter retracting said tool holder.

3. A feed head comprising a housing, a rotatable shaft mounted therein, a tool holder secured to said shaft for rotationtherewith and axial movement relative thereto, a spring for yieldingly maintaining said tool holder in normal retracted position relative to said shaft, a fixed member on said shaft and an opposed push member mounted on said shaft adjacent thereto and movable axially of said shaft, a plurality of centrifugally actuated members surrounding said shaft and maintained between said fixed member and said push member, a spring yieldingly maintaining an intimate contact between said fixed member, said push member and said centrifugally actuated members, a releasable connection between said push member and said tool holder, and means for releasing said connection upon axial movement of said tool holder to a predetermined point.

4. A feed head adapted to move a tool rotating at a substantially constant rate and at a predetermined pressure towards a work piece and comprising a power driven rotating shaft, a sleeve secured to said shaft, a tool holding member slidable longitudinally inside said sleeve and secured thereto for rotation therewith, a plurality of centrifugally'actuated weight members disposed about said sleeve, a fixed member secured to said sleeve adjacent one end of'said weights, a push member slidably mounted on said sleeve adjacent the other end of said weights, and a releasable connecting member carried by said'push member and contacting with a stop on said tool holding member to effect sliding movement thereof relative to said sleeve upon movement of said push member, a release member for releasing said connecting member, and a spring for returning said tool holder after release of said connection.

5. A feed head for feeding a rotating tool into a work piece, comprising an axially movable rotating tool holder, radially movable weights mounted to be revolved around an axis and connected to move the tool holder toward the work piece as the weights move outwardly from the axis. means to rotate the tool and revolve the weights, and a compression spring interposed between the tool holder and the radially movable weights and adapted to oppose the outward movement of the weights and substantially to balance by an increase in the opposed forces exerted by said spring'theincrease in the centrifugal forces developed in said weights, said spring being relatively shorter than the stroke of the tool whereby the increase in the resisting forces of the spring due to axial movement of the tool holder'is substantially equal in rate and amount to the in- -at a substantially constant rate and at a predetermined pressure towards a work piece and comprising a power driven rotating shalt, a sleeve secured to said shaft, a tool holding member work piece.

slidable longitudinally inside said sleeve and secured thereto for rotation therewith, a plurality of'centrifugaliy actuated weight members disposed about said sleeve, a iixed member secured to said sleeve adjacent one end of said weights, a pusher'member slidably mounted on said sleeve adjacent the other end of said weights, means connecting said pusher member to said tool holding member, and a'spring opposing the movement of said pusher member under the force of the centrifugalweights, said spring being adapted to be stressed by the increase in the forces exerted movement of said members being adapted to produce a component force acting along the axis of rotation of saidtool spindle to feed said tool spindle toward said work piece, an adjustable releasemember adapted to disengage the driving connection between said weight members and said tool spindle upon a predetermined movement thereof, and a resilient member acting on said weights to regulate the rate of outward movement thereof and the pressure exerted on said tool spindle and toreturn' said weights to their original positions after feeding the tool spindle a predetermined distance toward the cmunn E. amounts. 

